According to a telephone answering machine in the prior art, a conventional and normal response message has been sent in response to an incoming call, for example "This is 421-2266 Hashimoto Corporation but unfortunately the officer in charge is absent. However, would you speak and record your message after beep tone? Thank you." More recently, however, various calling systems have been established including collect calls, credit card calls, etc. In particular, collect calls and credit card calls employ a charging system in which a calling party is not connected unless the called party agrees to pay the charge. Thus, even if an automatic telephone answering machine responds at that time, a telephone operator normally refuses to connect the line unless the answering machine contains an acceptance term. If the answering message were simply to include a message accepting a collect call or a credit card call, e.g., a simple message "collect call OK" inserted between normal answering messages, a telephone operator could connect the incoming call to the telephone answering machine. Such a provision will make the use of answering machines much more widespread. However, it should be noted that, if a collect call is automatically accepted, nuisance calls or other unnecessary calls might often result in an increased burden of telephone charges against the subscriber.
There is thus a need in the prior art to provide a telephone answering machine capable of selectively accepting collect calls under controlled conditions.